Flush valve

ABSTRACT

Described here are flush valves for delivering a selected amount of water from a toilet tank into a toilet bowl, particularly collapsible flush valves having substantial durability and resistance to wear and deleterious chemicals. These flush valves have a collapsible member extending from above the surface of the water in the toilet tank to the tank outlet in the normal (closed flush valve) state. Collapsing the flush valve allows water to flow into the toilet bowl through the flush valve until the toilet tank is drained to the level of the collapsed flush valve and buoyancy is restored. Flush valves may be made of a material that does not substantially deteriorate in the presence of halogen-containing toilet disinfectants, and the outer surface (the water contacting surface) of the flush valves may be a single continuous piece.

FIELD

Described here are flush valves for delivering a selected amount of water from a toilet tank into a toilet bowl, particularly collapsible flush valves having substantial durability and resistance to wear and deleterious chemicals. Also described are methods of making and using the described valves. These flush valves typically include a collapsible member extending from above the surface of the water in the toilet tank to the tank outlet in the normal (closed flush valve) state. The flush valve is relaxed in the extended (closed) position. Collapsing the flush valve allows water to flow into the toilet bowl through the flush valve until the toilet tank is drained to the level of the collapsed flush valve and buoyancy is restored. The valves may be made of a material that does not substantially deteriorate in the presence of halogen-containing toilet disinfectants. At least the outer surface (the water contacting surface) of the flush valves may be a single continuous piece.

BACKGROUND

Most residential toilets use a flapper valve to regulate the passage of water from the toilet tank to the toilet bowl. A toilet is typically flushed by depressing the flush handle to lift the flapper valve, thereby allowing water in the toilet tank to exit into the bowl. Water continues to flow from the toilet tank into the bowl until the flapper valve pivots back down to once more seal the tank, allowing the toilet tank to refill.

Water conservation is increasingly important to water districts and to individuals faced with finite (or often dwindling) supplies, greater costs, and often growing demand for water resources. Toilets are the largest single water user in most homes, and flapper valves are the number one source of household water leakage. The flapper valve is prone to leakage because it is a moving seal that must be unsealed and resealed with every flush. According to a study conducted by the US Department of Housing and Urban development, 20% of household toilets leak, including 12% of low-flush toilets, primarily due to failure of the flapper valve.

A number of factors can contribute to leakage or failure of flapper valves. For example, debris can become lodged between the flapper and its seating seal (valve seat). Moreover, the flapper valve is ordinarily submerged in the toilet tank, and water and/or toilet bowl cleansers may corrode, rot or swell the flapper valve. Halogenated toilet bowl cleaners are particularly destructive to flapper valves. Further, flappers can warp or deform due to swelling or age. Algae can also grow on the flapper valve parts, adversely affecting performance. Finally, flapper valves may become misaligned with continuous use. Ironically, flapper valve leakage often increases after replacement of an existing flapper valve, perhaps because the new flapper valve is mismatched to the existing valve seat. There are currently no “standard” flapper valve geometries and it is difficult to know which valves to use to replace existing valves.

It is desirable to provide a flush valve which is less likely to leak, and which may be readily adapted to existing toilet tank designs. Currently, there are no commercially available flush valves that significantly resist leaking and are resistant to corrosion by the strongest available toilet bowl cleansers.

Two similar types of flush valves have been suggested to replace flapper valves: collapsible tubes, and siphon-type flush valves.

U.S. Pat. Nos. 6,381,764 and 6,199,221 to Stalhut show a toilet tank flush valve with a collapsible tube attached by O-rings to the tank outlet and also to a float which is capable of switching between high and low buoyancy. The valve is operated by depressing an actuating rod held in the middle of the collapsible tube. Similar collapsible tube valves are shown in U.S. Pat. No. 6,397,404 to Ferreyra et al., U.S. patent application No. 2003/0233703 to Parker, U.S. Pat. Nos. 3,183,526 and 3,280,407 to Aaron, U.S. Pat. No. 815,661 to Vissing, and U.S. Pat. No. 692,611 to Burgum.

U.S. Pat. No. 6,473,912 to Preciado-Villanueva shows a siphon flush valve in which a sliding conduit is attached (by a fixing means such as adhesives or mechanical means, column 3, line 65) to a fixed conduit and attached to a flow-directing element. The valve is operated by pushing down on the flow-directing element so that water begins to siphon into the sliding conduit. Similar collapsible tube valves are shown in U.S. Pat. No. 386,918 to Demarest.

None of the cited prior art suggests the device and methods described and claimed below.

SUMMARY

Described here are flush valves and methods for installing, using and making them. In particular, this application describes collapsible flush valves having substantial durability and resistance to wear and deleterious chemicals. The flush valves described herein may be used to controllably deliver a selected amount of water from a toilet tank into a toilet bowl without using a valve seat, because the flush valve operates by buoyantly holding the opening into the tank outlet port above the surface of the water in the toilet tank until the toilet is flushed.

In one version a flush valve for controllably delivering a selected amount of water to a toilet bowl from a toilet tank comprises a collapsible member configured to extend from the water surface of water in the toilet tank down to the tank outlet in a first or extended position. This extended position is maintained when the flush valve is “closed,” preventing the flow of water from the resting toilet tank into the toilet bowl. The flush valve maintains the level of water in the toilet tank by not allowing it to flow into the toilet bowl. The flush valve may release water from the toilet tank through the tank outlet by assuming a second position in which the collapsible member of the flush valve is longitudinally collapsed. The flush valve may be in the “relaxed” position (meaning there are minimal, if any, spring forces acting on the collapsible region of the flush valve collapsible member) when the flush valve is extended in the toilet tank (the extended position). Since the flush valve spends most of its useful lifetime in the closed position, preventing toilet tank water from passing into the toilet bowl, reducing spring forces on the flush valve may substantially extend the lifetime of the flush valve. Further, the flush valve collapsible member may comprise one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions; for example, rubbers, polymers, or combinations thereof which do not break down or loose their material properties when exposed to halogen-containing toilet disinfectants in a toilet tank for extended amounts of time (e.g. weeks, months or years). Further, the flush valve does not have a valve seat, as would be found in flapper-type flush valves and other comparable flush valves.

In some versions, the flush valve collapsible member is fabricated as a single, continuous piece. In some versions, all of the outer surfaces of the flush valve that are exposed to toilet tank water when the tank is full, and the valve is closed, are made as a single piece. Thus, there are no (potentially leaky) connections between separate components of the flush valve.

In some versions, the flush valve may also include at least one ballast weight. Ballast weights may help overcome the forces preventing the flush valve from collapsing to “open” and allow passage of water from the toilet tank into the toilet bowl (e.g. spring forces, material buoyancy, etc). In some version, ballast weight may help apply force to collapse the flush valve. Because the neutral position of the flush valve is in the extended (flush valve closed) position, collapsing the flush valve may be facilitated by ballast weights. The weights may be attached anywhere on the flush valve, especially the upper region (closer to the surface of the water in the toilet tank), for example, on the bottom of the buoyant region of the flush valve.

In some versions, the flush valve collapsible member comprises a base region, a float region, and a collapsible member that are fabricated as a continuous single piece. Sinking the float region allows the collapsible member to collapse and allows water to flow through the collapsible member and out of the tank outlet (“opening” the flush valve). The collapsible region of the collapsible member may be a collapsible bellows.

In some versions, the flush valve is opened by pushing on a tipping actuator. Thus, the flush valve may include a tipping actuator for sinking the float region of the flush valve.

In some versions, the base region, float region, and collapsible member of the flush valve are fabricated as a single piece by molding. In some versions, this molding is injection molding. In other versions, this molding is blow molding.

In some versions, the collapsible member may have a continuous spiral thread. For example, the “bellows” ridges of a collapsible member may actually be one or more continuous ridges spiraling around the outer edge of the collapsible region from the top (near the water surface) to the bottom (near the tank outlet port). The entire flush valve may be tapered (e.g. may be wider at the top than the bottom), or just the collapsible member may be tapered. Tapering may assist in fabricating the flush valve as a single continuous piece. Similarly, the flush valve may be radially symmetrical, which may also facilitate fabrication as a single piece.

The flush valve may be fabricated from a polymer such as a polyolefin. In particular, the flush valve may be fabricated from a Very Low Density Polyethylene (VLDPE, for example, FLEXOMER DFDA-1095 NT from DOW Chemical Company, or EXACT(™) 5371 from ExxonMobile Chemical), Ultra Low Density Polyethylene (ULDPE, for example, ATTANE® 4404 G from DOW Chemical Company), or soft vinyls (such as Tygon®).

In some versions, the flush valve further comprises a longitudinal shaft coupled to the collapsible member (for example, at the base region) wherein the shaft is configured to substantially guide the flush valve when the collapsible member collapses. The shaft may also include “stops” preventing the upper opening into the flush valve from collapsing beyond a set position. The shaft may be centrally positioned in the lumen of the flush valve (e.g. positioned near the long axis of the flush valve) or may be positioned off of the center (including external to the lumen of the flush valve).

Also described herein are flush valves for controllably delivering a selected amount of water to a toilet bowl from a toilet tank, the toilet tank having a water surface and a tank outlet, comprising a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank. The collapsible member is further configured to release water from the toilet tank through the tank outlet when it collapses longitudinally and takes a second, collapsed, position. The flush valve collapsible member comprises one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions. These flush valves also do not have a valve seat. In one version, the collapsible member is fabricated as a single continuous piece.

In one version of the flush valve, the collapsible member is configured to be substantially relaxed in the extended position. In some of these versions, the flush valve further comprises a ballast weight. The flush valve collapsible member may comprise a base region, a float region, and a collapsible member; sinking the float region allows the collapsible member to collapse and allows water to flow through the collapsible member and out of the tank outlet.

In some version of the flush valve, the flush valve further comprises a tipping actuator for sinking the float region of the flush valve. In some versions of the flush valve, the base region, float region, and collapsible member are fabricated as a single piece by molding, for example, injection molding or blow molding.

In some versions, the collapsible region of the flush valve is a collapsible bellows; in some versions this collapsible bellows has a continuous spiral thread (or ridge) at the bellows fold, extending from the top of the flush valve to the bottom. In some of these versions, the collapsible bellows is tapered.

The flush valve may be fabricated from a rubber, a polymer, or a combination thereof. In one version, the flush valve is fabricated from a polyolefin, in particular a Very Low Density Polyethylene (VLDPE, for example, FLEXOMER DFDA-1095 NT from DOW Chemical Company or EXACT(™) 5371 from ExxonMobile Chemical), Ultra Low Density Polyethylene (ULDPE, for example, ATTANE® 4404 G from DOW Chemical Company,), or soft vinyls (such as Tygon®).

In some versions, the flush valve further comprises a longitudinal shaft coupled to the collapsible member wherein the shaft is configured to substantially guide the flush valve when the collapsible member collapses.

Also described herein are flush valves for controllably delivering a selected amount of water to a toilet bowl from a toilet tank, the toilet tank having a water surface and a tank outlet, comprising a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank. The flush valve is further configured to release water from the toilet tank through the tank outlet in a second, longitudinally collapsed, position. The flush valve further comprises a ballast weight sufficient to collapse the collapsible member.

In some versions, the flush valve also comprises one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions. In some versions, the collapsible member is fabricated as a single continuous piece is configured to be substantially relaxed in the extended position.

Also described herein are flush valves for delivering water to a toilet bowl from a toilet tank comprising a base region configured to connect to the outlet port of a toilet tank, a floatable and sinkable float region having an opening that is held above the surface of the water when the float region is floating, and wherein the float region is linked to the base region through a collapsible member extending from the base region to the float region. The base region, float region and collapsible member are fabricated as a single piece. Sinking the float region allows water to flow through the opening of the float region and out of the outlet port of the toilet tank. In some versions, the flush valve further comprises a ballast weight. In some versions, the flush valve further comprises a tipping actuator for sinking the float region of the flush valve. In some versions, the collapsible member is relaxed in the extended position.

In some versions, the flush valve may also include a flow cone attached to upper region of the flush valve (e.g. the float region) configured to modify the passage of water into the opening of the float region.

Also described herein are flush valves for delivering water to a toilet bowl from a toilet tank comprising a molding-formed collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank in this extended position. The flush valve is further configured to release water from the toilet tank through the tank outlet when the collapsible member of the flush valve collapses into a second longitudinally collapsed position. This version of the flush valve has a collapsible member that is spirally threaded. Further, the flush valve has no valve seat. In some versions this flush valve is tapered.

In some versions, the flush valve further comprises a ballast weight. In some versions, the flush valve further comprises a tipping actuator for sinking the float region of the flush valve. In some versions, the collapsible member is relaxed in the extended position.

Also described herein are methods of using the described flush valve variations. In general, the flush valves described herein may be used to provide water from a toilet tank into a toilet bowl by at least partially sinking the flush valve. In some versions, the flush valve is partially sunk by applying force (e.g. by pushing) on a tipping actuator. In some versions, the tipping actuator applies force to the upper portion of the flush valve (e.g. a float region) to collapse the collapsible member of the flush valve.

Also described herein are methods of using a flush valve comprising at least partially sinking a float region of a flush valve in a toilet tank having an outlet port in fluid connection with a toilet bowl. The flush valve comprises a base region configured to connect to an outlet port of the toilet tank, a variably buoyant float region configured to switch between a high buoyant state and a low buoyant state, and having an opening that is held above the surface of the water when the float region is highly buoyant, wherein the float region is linked to the base region through a collapsible member extending from the base region to the float region. The float region and the collapsible member are fabricated as a single piece from one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions.

Also described herein are methods of using a flush valve in a toilet tank containing water comprising at least partially sinking a flush valve. The flush valve comprises a collapsible member configured to extend from the water surface to the tank outlet in a first or extended position and to maintain the water in the toilet tank, and the collapsible member is further configured to release water from the toilet tank through the tank outlet in a second, or longitudinally collapsed, position. The collapsible member comprises one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions, is fabricated as a single continuous piece. The collapsible member is configured to be substantially relaxed in the extended position.

Also described herein are methods of installing a flush valve in a toilet tank, where the toilet tank has an outlet port in fluid connection with a toilet bowl. The method of installing the flush valve comprises providing a flush valve and installing the flush valve onto the outlet port of the toilet tank. The flush valve comprises a base region configured to connect to the outlet port of a toilet tank, a variably buoyant float region configured to switch between a high buoyant state and a low buoyant state, and has an opening that is held above the surface of the water when the float region is highly buoyant. The float region of the flush valve is linked to the base region through a collapsible member extending from the base region to the float region. The float region and the collapsible member are fabricated as a single piece. In some versions, the flush vale is installed by tightening a nut.

Also described herein are methods of fabricating a flush valve comprising injection molding a flush valve. The flush valve to be injection molded comprises a base region configured to connect to the outlet port of a toilet tank, a variably buoyant float region configured to switch between a high buoyant state and a low buoyant state, having an opening that is held above the surface of the water when the float region is highly buoyant, wherein the float region is linked to the base region through a collapsible member extending from the base region to the float region. The float region, base region and the collapsible member of the flush valve are injection molded as a single piece. In some versions, the flush valve is injection molded from one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions. In some versions, the flush valve is tapered.

Also described herein are methods of fabricating a flush valve comprising injection molding a collapsible member configured to extend from the upper water surface of a substantially filled toilet tank to the tank outlet in a first extended position to maintain the water in the toilet tank, and further configured to release water from the toilet tank through the tank outlet in a second, longitudinally collapsed, position, wherein the collapsible member is further configured to be substantially relaxed in the extended position. The collapsible member is injection molded from one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments or variations are now described by way of example with reference to the accompanying drawings.

FIG. 1 shows a schematic illustration of an integrated flush valve;

FIG. 2 shows the flush valve of FIG. 1 in the collapsed position;

FIGS. 3A to 3C show top views of the insides of the upper float chamber;

FIG. 4 shows a schematic illustration of another version of an integrated flush valve;

FIG. 5A shows an integrated flush valve having a tapered bellows;

FIG. 5B shows an integrated flush valve;

FIG. 6 shows an integrated flush valve installed in a toilet tank;

FIGS. 7A to 7C illustrate the activation of an integrated flush valve.

DETAILED DESCRIPTION

Described here are integrated flush valves for use in toilet tanks, methods of manufacturing the flush valves, and methods of using the flush valves. In the drawings, reference numeral 10 generally denotes an exemplary embodiment of an integrated flush valve. For the sake of brevity, an integrated flush valve will be referred to as a “flush valve.”

FIG. 1 shows a flush valve 10 in an extended position. The flush valve is a collapsible member which comprises a hollow integrated unit having regions corresponding to an attachment base region 101 which attaches to the output port of a toilet tank (tank outlet), a collapsible tube (or bellows or member) region 103 that prevents the passage of water when extended and allows the passage of water when the tube is collapsed, and a float region 105 which may provide an upward buoyancy when the flush valve is in the resting state. These regions of the flush valve are preferably sub-regions of a single integrated component.

Because the flush valve in FIG. 1 is integrated, all of the flush valve surfaces which contact fluid (e.g. water) in the inactive state (when the valve is “shut”) are continuous. Thus, there is no need for seals or connections between the different regions of the flush valve. This has many advantages over flush valves which comprise separately joined regions, including cost and durability. The fewer seals that a flush valve has, the less chance it will leak. Further, flush valves with fewer components are generally less expensive to produce than valves requiring the assembly of multiple components.

The flush valve shown in FIG. 1 is formed as a single piece, and thus does not have any joints or seals which may degrade and potentially leak. The outer diameter of the flush valve provides sufficient clearance to allow lateral (“up/down”) movement within the tank. As illustrated in FIG. 6, the outer surface of the flush valve (shown in FIG. 1) is exposed to water in the toilet tank, and acts as a barrier, preventing water in the toilet tank from flowing into the tank outlet port until the flush valve is activated. The inner region of the flush valve 109 is hollow, and forms a continuous fluid connection with the outlet port of the toilet tank.

FIG. 2 shows the flush valve of FIG. 1 in the longitudinally collapsed position. The collapsible member of the flush valve 10 collapses to reduce the height of the flush valve. The change in height may depend on the structure of the collapsible member. When the collapsible tube is a bellows (as shown), the collapsible tube height changes by folding, accordion-style. The collapsible tube 103 collapses when the float region loses buoyancy, for example, when the float region is tilted and takes on water. Losing buoyancy means that the upper, float region of the flush valve will sink, allowing water to flow through the central channel of the flush valve and out of the tank through the outlet port.

The inner region of the flush valve 109, may modify the activity of the flush valve. In one version, the flush valve includes inward radiating struts 301 to support a rod or shaft. The inner region may also include additional attachment sites. In one version, the inner diameter of at least a region of the flush valve (e.g. the collapsible member) is optimized to increase the fluid flow exit rate.

Attachment Base Region

The attachment base region 101 may attach into the tank in the same way as would any standard flush valve attachment. In one version, the attachment region attaches by a fixed elastomeric seal compressed with a large plastic nut. Thus, the outer wall or the inner wall of the attachment base region may be threaded or otherwise textured to facilitate attachment to the outlet port of the toilet tank.

The inner diameter of the attachment base region may be adapted to modify the flow of liquid from the toilet tank, or it may include supports or struts. Supports or struts may be useful to provide enhanced strength for the attachment base region. Further, supports or struts may be used to support a rod or shaft in the flush valve. In one version, the inner diameter of the attachment base region is narrower than other regions of the flush valve. In one version, this narrowing of the inner diameter of the attachment base region enhances the flow rate or pressure entering into the toilet bowl.

The inner surface of the attachment base region may be an integral part of the flush valve, or it may have additional materials attached to it. The outer surface of the attachment base region, as with the outer surface of the entire flush valve, is preferably made as one single continuous piece.

In one version of the flush valve, the base region of the flush valve comprises a sleeve which attaches to an attachment adapter for sealing the base of the toilet tank to the tank outlet port. An attachment adapter may include, for example, a threaded nut adapter. In one version, one end of the threaded nut adapter is attached to the base region of the flush valve. The threaded nut adapter passes through the tank outlet port, and the nut is screwed onto the threaded adapter on the opposite side. A water tight seal is formed when the nut is tightened, forcing the base region of the flush valve against the bottom and/or sides of the outlet port. This type of attachment adapter works particularly well when the base region is made of a compressible elastomeric material.

Flush valves as described above may be used with existing (“standard”) toilet tanks. Thus, the outer diameter, thickness, height and other dimensions of the attachment base region may be adapted to fit the dimensions of any existing toilet tank, particularly the outlet ports for the commercially available toilet tanks. Of course, the dimensions of the attachment base region may be adjusted to fit virtually any toilet tank output port.

In one version, the outer diameter, thickness and height of the attachment base region are adapted to attach to a toilet tank having an outlet port 2 inches in diameter. In one version, the outer diameter thickness and height of the attachment base region are adapted to attach tot a toilet tank having an outlet port 3 inches in diameter. The actual diameter of the outlet port may be determined based on industry or government standards.

Collapsible Member

The collapsible member (collapsible tube region) 103 allows the flush valve to change height by elongating or compressing (collapsing) when the float region gains or loses buoyancy. In one version, the collapsible tube is a bellows.

Preferably, the collapsible member is capable of undergoing many thousands of compression/expansion cycles over a lifetime of many years. The collapsible region collapses (contracts) each time the flush valve is activated to allow fluid to flow out of the flush valve. At the end of the flush cycle, the collapsible member expands to prevent fluid from flowing out of the flush valve.

The structure of the collapsible member may be optimized for durability, strength, and function. In one version, the wall thickness of the collapsible member is substantially uniform. In one version, the wall thickness is adjusted to accommodate the repeated motions of the collapsible member; for example, by reinforcing the parts of the collapsible member requiring greater material strength.

The collapsible member of the flush valve shown in FIGS. 1 and 2 are bellows having one or more continuous ridges that coil around the collapsible member. This results in a threaded appearance. The dimensions of the “threads” in the collapsible tube may, in part, determine how compressible the collapsible region is (e.g. how far the flush valve collapses or changes its height). The threaded collapsible member is particularly advantageous in fabricating the integrated flush valve, as described below. A collapsible tube region (or a region of a collapsible member of a flush valve) having one or more continuous threads has one or more ridges (threads) that begin at the top of the collapsible region and continue to the bottom of the collapsible region. Thus, the continuous thread(s) run, screw-like, around the collapsible region. A continuous thread may be substantially continuous, meaning that the thread may be interrupted (for example, by some other structure) but then continue as if it had not been interrupted.

In one version, the collapsible tube has two or more threads forming the bellows. The threads are intertwined around the perimeter of the collapsible tube and their starting points (e.g. at the top or bottom of the collapsible member) may be equally spaced from each other. Balancing the threads this way may prevent unequal compression and torsion of the collapsible tube.

The dimensions of the collapsible member may vary depending upon the design specifications. Thus, a fully extended collapsible member should allow the upper surface of the flush valve to extend beyond the maximum desirable tank fill level. The collapsed form of the flush valve should place the opening of the collapsible member of the flush valve at approximately the high of the completed tank flush level. Thus, if a six liter flush is to be delivered, the collapsible member should collapse at least to a height which will deliver six liters of fluid. A selected amount of water can be controllably delivered by the flush valve; for example by selecting the height to which the flush valve collapses.

In some versions, the collapsible member will have a spring modulus which may effect the operation of the flush valve. Thus, if the collapsible member is a bellows, the dimensions and the material chosen for the flush valve may, in part, determine the spring modulus of the flush valve. In some cases, the spring modulus describes the force required to move the collapsible member either in expansion or compression. In one version, the spring modulus is adjusted, for example, by the material used to form the flush valve, or by treating the flush valve (e.g. by heat) to pre-set the resting state of the collapsible tube.

In one version, the collapsible tube is substantially extended in the neutral (relaxed) position. Thus, the collapsible tube, and therefore the flush valve, relaxed in the extended position in the filled toilet tank. In this extended state there are minimal (or perhaps no) spring forces acting on the collapsible tube. This “low stress neutral position” (or zero-stress neutral position) may enhance the durability and lifetime of the flush valve, as described further below. The “low stress neutral position” is that position where movement of the collapsible member along its axis, i.e., expanding or contracting, will exhibit a positive or negative spring force. When the flush valve is substantially extended, the collapsible region of the collapsible member (flush valve) is extended longitudinally along the long axis of the flush valve; in a water filled toilet tank the substantially extended position is one in which the top portion of the collapsible member is above the surface of the water.

In one version, the collapsible member of the flush valve is tapered so that the inner diameter of the flush valve is greater in the upper part of the collapsible member than it is in the lower part of the collapsible member. For example, see FIG. 5A. Thus, the collapsible member appears tapered. In one version, the collapsible member is tapered and threaded.

Alternatively, the collapsible member may be a pliable region. In one version, the collapsible member comprises a pliable sheet formed into a collapsible member. In this version, the collapsible member may be laterally supported by adding an additional internal support, such as a spring or other framework. Thus, although the collapsible member is sufficiently pliable to collapse when the float region loses buoyancy and sinks, the collapsible member is also sufficiently laterally supported to prevent the fluid pressure from constricting the collapsible member when the float region is buoyant. The outer (fluid-contacting region) of the flush valve is a single continuous surface, preventing leakage and the need for sealing the different regions of the flush valve.

Although the collapsible tube is shown as substantially cylindrical, the collapsible tube may be any cross-sectional shape, including but not limited to, circular, elliptical, or polygonal (e.g., triangular, square, etc).

Float Region

The float region of the collapsible tube provides upward buoyancy to the flush valve. In the inactive state (when no fluid flows into the flush toilet bowl through the flush valve), the float region holds the opening of the flush valve above the surface level of the water in the tank. In one version, the float region is a captured open volume defined by a lower surface 131 and a side rim 133, as shown in FIG. 1 and 2. The top rim 133 remains above the surface of the waterline when the flush valve is inactive so that no water leaves the flush valve from the toilet tank unintentionally. In the neutral position, the buoyant force of the float region overcomes the downward force of gravity (weight of the flush valve) and any spring forces from the collapsible tube. In one version, the collapsible tube has minimal spring forces in the neutral position.

The dimensions of the outer parts of the float region (e.g. the rim 133 and the lower surface 131) may vary, for example, depending upon the materials chosen and the size of the tank in which the flush valve is to be used. In one version, the rim 133 height is chosen to be relatively low so that the float region may be readily tipped, making the flush valve sensitive to user activation. In one version, the lower surface is larger to increase buoyancy. In one version, the thickness of the rim and lower surface are selected to enhance buoyancy while providing adequate structural support.

FIGS. 3A to 3C show a top view of features of the inner portion of the float region 105. In FIG. 3A, the center portion of the float region interior contains an opening into the inner chamber of the collapsible member 301, which is in fluid connection with the tank outlet port through the attachment base region. In one version, the opening 301 is surrounded by a rim 315. When the flush valve is activated by tipping the float region, water will enter the inner portion of the float region and reduce the buoyancy, causing the float region to sink. A raised rim 315 slows water from draining out of the float region into the collapsible member, which may help sink the float region. The height of the rim may vary. A taller inner rim means more water will be captured by the float region after the valve is opened. The more water captured, the greater the weight due to water to “sink” the float region. The rim 315 may have one or more small openings to allow water to eventually drain from the inner portion of the float region. These openings help restore buoyancy at the end of the flush valve open cycle, by allowing water to drain from the float region.

FIG. 3B shows a version of the float region in which the entrance to the collapsible member is partly occluded by support 320. The support 320 both modifies the flow through the flush valve and may help support a shaft or rod. A rod or shaft may pass through an opening 330 in the support 320. The dashed lines 303 indicate the location of the outer diameter of the collapsible member beneath the lower surface of the float region. In one version of the float region, the entrance to the collapsible member contains struts.

In one version of the float region shown in FIG. 3B, a rim 322 surrounds the entrance into the collapsible member. The rim 322 in FIG. 3B narrows the opening (modifying the flow into the collapsible member and out of the tank). The rim 322 is also raised above the lower surface of the float region. The lower surface of the float region may have holes 325 in the lower surface that empty into the collapsible member to allow slow drainage of water from the float region, for example, when restoring buoyancy. Alternatively, or in addition, the rim may have drainage holes.

FIG. 3C shows a version of the float region in which a flow cone has been added to modify the flow of water from the inner portion of the float region into the collapsible member and out of the flush valve. Beneath the flow cone (not shown) are holes in the lower surface that allow the float region to empty (as in FIG. 3B 325). The flow cone may be of different heights and widths. In one version, the flow cone has a curved surface to guide the water flowing into the flush valve and through the tank outlet port. The flow cone may be any height. In one version, the flow cone is low, so that the top of the flow cone is near the lower surface of the float region. In one version the flow cone is tall, so that the top of the flow cone is at least halfway up the wall height of the float region.

The overall shape of the float region 105 shown in FIGS. 1 to 3 is rectangular, however virtually any shape may be used. In particular, a symmetric shape (e.g. round) may be desirable. FIG. 4 shows an example of a circular float region 401. In one version, the float region is shaped to prevent contact with other parts of the toilet tank, such as the refill inlet, the walls of the tank, and the refill float.

The float region may also include adaptations for contact with a tipping actuator. For example, the flush valve may be actuated by tipping the float region so that it becomes at least partly submerged. The float region of the flush valve may be tipped by applying force to one or more parts of the float region. In one version, a tipping actuator applies force against the upper surface of part of the float region. In one version, float region includes a contact (or “landing pad”) specialization for contacting the tipping actuator. In one version, the upper edge of the float region is flanged to provide a more reliable contact region for the tipping actuator. In one version, the tipping actuator is attached to the float region.

In one version, the tipping actuator fits into a slot located on the side or top portion of the float region. The slot may be open at the top or may be closed, encircling the tipping actuator. The slot may help guide the tipping actuator into position with the float region of the flush valve. In one version, the tipping actuator remains within the slot during the entire flush cycle (as the flush valve collapses to open, and floats back to the neutral position once buoyancy is restored).

Ballast Weights

The float region switches from buoyant (floating at the top of the water in the tank) to non-buoyant (sinking to allow water into the toilet bowl). The neutral buoyancy of the float region may be modified by adding buoyant or non-buoyant weighting material (weights). In one version, additional weight (e.g. ceramic plastic, concretes, or metal weights) may be added to the float region. In one version the weighting material is ballast. Weights maybe adjustably added by a user or permanently affixed to the float region. In one version, weights are added to the inside of the float region. In one version, weights are added to the outside of the float region. Buoyant material may also be added to increase the buoyancy of the float region.

The density of the flush valve (e.g. the density of the material from which the flush valve is fabricated) may determine the weight of the flush valve. Most collapsible flush valves will be fabricated of a material having a density near enough to that of water so that when the flush valve is completely submerged, the flush valve will not sink (collapse) unless there is at least one additional force (e.g. spring forces, etc) acting on the collapsible member of the flush valve. Thus, it may be desirable to include ballast weight so that the flush valve will sink or collapse to the proper stopping position in the toilet tank and therefore empty the tank to an appropriate level.

In some versions of the flush valve, the collapsible member is relaxed in the extended position. Ballast weights may be helpful in these versions, particularly when the flush valve is composed of a material having a density which is sufficiently near (or less than) that of water. Thus, ballast weights, counterweights, springs, or some combination may be assist the flush valve in collapsing to the appropriate level from the relaxed (extended) position.

In one version, weights are made of a water, corrosion and/or chemically resistant material. For example, high density plastics, metals, ceramics, concretes, or any combination thereof may be used to make the weights. In on version, ceramics such as porcelain or concrete materials are used. Weights may be affixed to the float region passively (e.g. by sitting inside of the float region) or actively (e.g. by fastening to the float region). In one version, the float region includes a fastener at the bottom surface of the float region to which a weight may be attached.

Guiding Rod

In one version the flush valve includes a rod or shaft 501. FIG. 5B shows an example of a flush valve having a shaft 501 positioned in the long axis of the flush valve. The shaft attaches to the center of the base unit 101 to provide vertical guidance for the float and collapsible members of the flush valve. The shaft may also help prevent excessive tipping by a tipping actuator when a tipping actuator is used to trigger opening of the flush valve by applying a force against one side of the float region. The shaft may also engage with the upper region of the flush valve, though an opening 330 in a support 320 at the base of the float region.

The shaft shown in FIG. 5B is centrally located, however a guide shaft or rod may be positioned longitudinally anywhere it can help stabilize and guide the longitudinal (e.g. collapsing) motion of the flush valve. In one version the rod is located off-center in the lumen of the flush valve. In one version, the rod is located externally to the lumen of the flush valve. In one version, the flush valve includes a pocket for inserting the guide rod.

The shaft may guide the movement of the opening and closing of the flush valve. For example, the flush valve motion may be limited by the shaft. In one version, the shaft is rigid, and prevents excessive lateral motion of the flush valve. Thus, the flush valve may be prevented from interfering with other components in the toilet tank, for example. Some lateral (‘tipping’) motion may be desired, particularly when initiating opening of the flush valve. Limited lateral motion may be permitted when the flush valve includes a shaft, for example, by creating an opening through a support 320 in the base of the float region which has a larger diameter than the outer diameter of the shaft. In FIG. 3C, the opening 330 for the shaft is elliptical, allowing tipping, but limiting excessive lateral motion because of the guide rod which has a circular outer diameter. Furthermore, tipping is permitted in only the direction of the longer diameter of the elliptical opening 330.

A shaft may also limit vertical movement may of the flush valve. In one version, the shaft has a vertical stop (e.g. a region of greater diameter) preventing the float region from extending past the top of the shaft. Additional stops may be located at other regions on the shaft to limit the downward movement of the float region of the flush valve. For example, the flush valve may be prevented from falling to the bottom of the toilet tank in order to limit the amount of fluid passed per flush.

A vertical stop may also prevent the toilet tank from overflowing. If the water level in the tank fills above the upper rim of the flush valve float region when the flush valve is kept from extending further vertically by a vertical stop, the flush valve will activate, flush the toilet tank and preventing overflow of the tank.

In one version, the guiding shaft is hollow and allows water to pass through the output port of the toilet tank without opening the flush valve. In some versions, it may be desirable to pass a small volume of water into the toilet bowl without opening the flush valve, for example, when the tank is refilling following a flush cycle. Water may be directed through the central channel of the closed flush valve by an elbow joint connected to the tank inflow valve. In one version, the guiding shaft is located within the lumen of the flush valve and connected to the tank inflow valve, allowing some water to pass through the flush valve as the tank is refilling. The small amount of water passed into the tank after the flush cycle may enhance toilet bowl re-filling. In one version, the shaft is 0.5 inches in diameter, and has a wall thickness of at least 1/16^(th) of an inch.

Durability

Flush valves described and claimed here operate in the water-filled toilet tank environment. In addition to water, the toilet tank may comprise chemical, enzymatic, or other additives (e.g. toilet bowl cleansers, deodorizers, etc.) which may detrimentally effect any components of the toilet tank and toilet, particularly the flush valve.

Further, the flush valve should operate over a reasonable lifetime of a toilet tank. For example, a flush valve may operate for at least a year, at least two years, at least five years, or at least ten years.

A flush valve should operate reliably in the harsh toilet tank environment. Thus, a flush valve should resist wear, handle repeated use, and resist stress cracking, as well as be substantially corrosion, water and/or chemically resistant. Deterioration of the flush valve may result in loss of surface integrity (e.g. cracking, tearing, or otherwise undesirably allowing water to leak through the flush valve, etc.), or loss of material strength (e.g. allowing regions of the flush valve to collapse due to water pressure, etc.), or loss of material characteristics (e.g. loss of flexibility during repeated opening/closings, etc.).

Resistance to Mechanical Stresses

In one version, the flush valve resists mechanical stress (e.g. cracking, creep and/or deformation) by minimizing the forces acting on the flush valve in the neutral (closed) position. In one version, the spring forces on the collapsible member are reduced or eliminated when the collapsible tube is in the extended position (the position that the collapsible tube would naturally be in when the flush valve is closed). Thus, the collapsible tube at rest is substantially extended. When the collapsible tube is collapsed, the spring forces oppose the compression of the collapsible tube. Since spring forces will only significantly act on the flush valve collapsible tube when it is opened, material fatigue may be decreased.

In the neutral state the toilet tank is lull of water, and the flush valve is closed; the float region is substantially at the surface of the water in the tank, and the collapsible member is substantially extended so that the upper region of the flush valve is held above the water surface. In practice, the majority of the lifetime of an installed flush valve is spent in this position. The float region and any weighting material (weights) displace a volume of water whose weight is equal to the combined weight of the float region and the weights in the neutral position. When the upper rim of the float region is forced below the surface of the water in the tank (e.g. by action of the tipping actuator), the float region is flooded, and is now negatively buoyant because of the added weight of the water in the float region. The negative buoyancy causes the float region to descend, or sink, within the toilet tank, to a predetermined stop position. Sinking the float region also causes the collapsible member to compress. If the collapsible tube is configured so that the spring force (e.g. material forces, etc) are minimized when the flush valve is in the neutral position, then the spring forces will be oppose the sinking of the float region when the collapsible region collapses.

The degree to which the float region is negatively buoyant is dependant upon the weight of the float region and any weighting material (e.g. ballast weights) as well as the density of the float region material, the weight of the flood water volume, and the force exerted upon the float region by the collapsible member, which varies with the position of the collapsible tube (e.g. spring forces). The force of the water moving from the tank into the central passage of the flush valve may also contribute a force component. Water empties from the tank and into the toilet bowl through the central passage of the negatively buoyant flush valve.

The flushing action of the flush valve is completed when the tank water level has been reduced so that the tank water level is at the same height as the rim of the float region (now at its lowest position), and after the residual flood water volume has sufficiently drained into the throat of the central passage of the flush valve. The float region then becomes positively buoyant as the weight of the residual flood water is reduced. Once buoyancy is restored, the float region of the flush valve rises in conjunction with an increasing tank water level.

In one version, the flush valve is designed so that material stresses acting on (and material fatigue of) the flush valve is reduced or minimized. In particular, material stresses acting on the collapsible member may be reduced or minimized, for example, by optimizing the size and thickness of the threads in the bellows-type collapsible tubes.

In general, the material chosen for all or regions of the flush valve (e.g. the collapsible member) may be selected to effect the mechanical properties (e.g. spring modulus) and durability of the flush valve.

Resistance to Chemical Degradation

Chemicals and components added to toilet water may be powerful corrosives or degrading agents which may otherwise reduce the durability, performance and lifetime of the flush valve. Thus, it is important that the flush valve, particularly the regions of the flush valve exposed to toilet tank water when the valve is closed, be resistant water and to some, most, or all of the corrosive or degrading agents. Materials resistant to degrading agents are materials that do not substantially deteriorate in the presence of degrading agents (e.g. halogen-containing toilet disinfectant solutions). Materials that do not substantially-deteriorate will maintain flush-valve integrity (e.g. prevent water from leaking through the flush valve); this includes maintaining material strength and material characteristics of the flush valve (e.g. flexibility and resistance to water pressure).

In one version, at least the outer surface of the flush valve comprises a material resistant to chlorine (Cl) containing compounds, ions, or agents. Cl-containing ions, compounds or agents include, but are not limited to, Cl⁻, percholorides, chlorides, chlorates, percholorates, (e.g. hydrochloric acid, hypochlorite bleach, trichloro-s-triazinetrione, etc.).

In one version, at least the outer surface of the flush valve comprises a material resistant to bromine (Br) containing compounds, ions, or agents. Br-containing ions, compounds or agents include, but are not limited to, bromine, oxides of bromine, hydrides of bromine, (e.g. sodium tetraborate pentahydrate, etc).

In one version, at least the outer surface of the flush valve comprises a material resistant to ingredients often present in commercially available toilet water additives, such as bowl cleaners, deodorants, etc. For example, the material comprising the flush valve may be resistant to ingredients in (or produced by) toilet water additives including isobomyl acetate, sodium carbonate, sodium sulfate, hydroxyethyl cellulose, cocamide MEA, sodium carbonate, FD&C Blue #1, sodium chloride, pine oil, sodium dodecylbenzenesulfonate, sodium C₁₄-C₁₆ olefin sulfonate, organic chlorine bleach, sodium tetraborate pentahydrate, Acid Blue #9, aluminum sulfinate, trichloro-s-triazinetrione, n-alkyl dimethyl benzyl ammonium chlorides, n-alkyl dimethyl ethylbenzyl ammonium chlorides, ammonium chlorides, isopropyl alcohol, sodium lauryl sulfate, ammonium ions (e.g. at concentrations of from 0.05 to 2.5 ppm free ammonia), and other halogen containing (and releasing) sanitizing agents (such as N-halogenated organic compounds, e.g., brominated phthalimides, p-toluene sulfonamides, azodicarbonamidines, hydantoins, glycoluracils, cyanurates, amines, melamines, N-chloro-phthalamide, N-bromo-phthalamide, N-dichloro-p-toluene sulphonamide, 2,5-N,N′-dichloro-azodicarbonamidine hydrochloride, N,N′-dichloro-dimethyl-hydantoin, N-bromo-N′-chlorodimethyl-hydantoin, N,N′-dibromo-dimethyl-hydantoin, N-bromo-N-chloro-diphenyl-hydantoin, bromocholoro-5,5-dimethylhydantonin, 1,3-dichloro-5-ethyl-5-methylhydantonin, 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), 1,3-dichloro-5,5-dimethylhydantoin (DCDMH), 1-bromo-3-chloro-5,5-dimethylhydantoin (BCDMH), dichloroisocyanuric acid and its sodium and potassium salts, trichloroisocyanuric acid (TCICA), hypochlorite ion-releasing agents (e.g., calcium hypochlorite and lithium hypochlorite, N,N,N,N-tetrachlorodimethyl-glycoluracil, N-bromo-N,N-dichloro-dimethylglycoluracil, N,N′-dibromo-dimethyl-glycoluracil, N,N,N,N-tetrachloro-glycoluracil, N,N-dichlorodichloroyl, N-bromo-N-chloro-sodium cyanurate, dibromo triethylene diamine dihydrochloride, bromo-chlorotriethylene diamine dihydrochloride and N,N,N-trichloro-melamine).

Of special interest are materials that have long-term resistance to chemicals used in resident toilet disinfectant compositions, which are often made into pills, pellets, or the like and placed in the toilet tank for extended periods. These compositions usually release chlorine (or other halogens) and related materials over extended lengths of time. For instance, many such compositions include as active disinfectant and cleansing components, halogen-releasing agents such as chloramines; chlorimines; chloramides; chlorimides; halogenated isocyanurates, including heterocyclic N-bromo and N-chloro cyanurates; halogenated melamines such as N,N,N-trichloromelamine; N-chlorosuccinimide; alkali metal or alkaline earth metal hypochlorites, e.g., calcium hypochlorite and lithium hypochlorite; halogenated phthalamides such as N-chloro-phthalamide and N-bromophthalamide; and the halogenated hydantoins, particularly halogenated 5,5-dialkyl-substituted hydantoins. Examples of particular hydantoins found in residential toilet disinfectants include 1-bromo-3-chloro-5,5-dimethylhydantoin, 1,3-dichloro-5,5-dimethylhydantoin, 1,3-dibromo-5,5-dimethylhydantoin, 1-bromo-3-chloro-5,5-diethylhydantoin, 1,3-dichloro-5,5-diethylhydantoin, 1,3-dibromo-5,5-diethylhydantoin, 1-bromo-3-chloro-5-methyl-5-ethylhydantoin, 1,3-dichloro-5-methyl-5-ethylhydantoin, 1,3-dibromo-5-methyl-5-ethylhydantoin, 1-bromo-3-chloro-5-methyl-5-n-propylhydantoin, 1,3-dichloro-5-methyl-5-n-propylhydantoin, 1,3-dibromo-5-methyl-5-n-propylhydantoin, and the like.

Toilet cleaning agents may release (typically at a controlled, substantially constant, rate) halogens into the tank water at a concentration in the range of 0.5 to 5 ppm perhaps with values of pH ranging of from about 6.5 to about 10, over its entire life of 2 to about 4 months of constant contact with water. A single block may deliver a uniform level of halogen (0.5-3 ppm) for about 1700 to 2100 flushes and will be completely dissolved at the end of its useful life.

In one version of the flush valve, the fluid-contacting surfaces of the flush valve comprise a material or materials substantially resistant to the toilet water chemical additives. Examples of such appropriate resistant materials are described below in the section titled “Materials,” and may include polyolefins.

In one version, at least the outer surface of the flush valve comprises a material resistant to enzymes. In one version, at least the outer surface of the flush valve comprises a material resistant to amines. In one version, at least the outer surface of the flush valve comprises a material resistant to borax.

Fabrication

The flush valve described herein may be fabricated as a single continuous piece, for example, by injection molding or blow-form molding. In particular, fabrication of a single continuous piece means that all (or most) of the surfaces of the flush valve that contact water when the flush valve is “closed” in a filled toilet tank are a single integrated piece (e.g., without seals or connectors). Minimizing the number of components of the flush valve reduces the cost, and complexity and likelihood of failure or leakage of the flush valve. In one version, the flush valve base region, collapsible member and float regions are all regions of a single piece such that these three regions do not require further connecting or seals. In one version, the base region and the collapsible member are fabricated as a single piece that does not require further connection or seals. In one version, the collapsible member and the float region are fabricated as a single piece that dose not require further connection or seals.

In one version, the flush valve is injection molded. In general, injection-molding involves the steps of: (a) feeding a composition into the heating chamber of a molding machine and heating the composition to form a molten composition; b) injecting the molten composition into a mold cavity; c) maintaining the composition in the mold under high pressure until it cools; and d) removing the molded article.

In one version of the flush valve, flush valve is tapered to facilitate removal of the flush valve from the mold. In one version, the injection mold has a central core for shaping the inner surface of the flush valve. Bellows-type structures, such as the collapsible member of some versions of the flush valve, are difficult to remove from a central core of an injection mold once formed. However, when the collapsible tube is configured as a continuous “screw” shape (as described above), the collapsible member of the flush valve may be formed between the walls of an injection mold, and later “unscrewed” to remove the central mold core.

FIG. 5A shows a flush valve which is formed as a single piece. The flush valve of FIG. 5A has a number of features which facilitate fabrication by a molding technique such as injection molding. First, the collapsible member 103 has one or more threads 501 which extend from the upper portion all the way to the base region 101. Thus, the flush valve may be “unscrewed” from the central region of a mold. Second, the collapsible member of the flush valve shown in FIG. 5A is tapered. The inner diameter of the flush valve generally decreases from the bottom of the flush valve to the top of the flush valve (from the base region to the float region). Tapering makes removal from a central region of a mold easier; particularly when combined with the threaded collapsible tube design described above. In threaded and tapered versions of the flush valve, the central core of a mold can be withdrawn after unscrewing the collapsible member even a short distance (e.g. a quarter of a rotation). Finally, the flush valve of FIG. 5A is substantially radially symmetrical, further facilitating removal of the central region of a mold. Radial symmetry allows a central mold to be loosened by rotation, a feature that is particularly helpful when the collapsible region of the flush valve is threaded.

Any of the features described above for the version of the flush valve shown in FIG. 5A may be used alone or in combination with other features to facilitate fabrication of the flush valve.

The flush valve described herein may be fabricated by any method capable of creating an integrated flush valve. Thus, variations and modification of the general injection molding technique described above are contemplated, including but not limited to reactive injection molding, rotational molding, thermoforming, vacuum molding, blow molding, gas-assist or water-assist injection molding, etc.

Once a flush valve is fabricated, it may be treated or further processed. It is desirable to minimize amount of post-molding processing that a flush valve undergoes, to simplify the fabrication process and to reduce the cost of fabrication. Example of post-fabrication processing includes but is not limited to: cutting, shaping, heating, baking, coating, and connecting to additional components.

In one version, the flush valve is treated after fabrication to set the neutral (relaxed) shape of the collapsible member by expanding or compressing the collapsible member and applying heating to reset the shape. In some versions, the flush valve is fabricated so that the collapsible member is substantially extended in the neutral position.

In one version of the flush valve, the outer surface of the flush valve is fabricated as a single piece, by injection molding.

Materials

The flush valve or its components may be made of one or more materials capable of withstanding the environment of the toilet tank while maintaining the integrity of the outer (fluid contacting) surface after many opening/closing cycles of the flush valve. For instance, useful materials include various polymers (including thermoplastics and thermoset plastics), rubbers, and mixtures thereof. Of particular value are moldable thermoplastics. Examples of useful polymers include, but are not limited to polyolefins, such as polyethylenes (e.g. Very Low Density Polyethylene (VLDPE), Ultra Low Density Polyethylene (ULDPE), plastomers, etc., particularly those having a density between about 0.86 to about 0.92 g/cc), polypropylenes, chlorinated vinyl resin selected from the group consisting of polyvinyl chloride, postchlorinated polyvinyl chloride, polyvinylidine chloride and copolymers thereof, and chlorinated rubbers, polyvinyl chlorides (e.g. soft vinyls such as Tygon®), and mixtures thereof, such as thermoplastic elastomers (e.g. thermoplastic vulcinates and other blends of polypropylene and/or polyethylene with rubbers, etc.).

In one version, the outer surface of the flush valve is made of a material which is corrosion and/or degradation resistant. As described above, it is beneficial that the flush valve be made of a material that is resistant to chemicals present or added to toilet water, such as chlorines, bromines, enzymes and amines, etc. (including those described above in the section entitled “Resistance to Chemical Stress”). In one version, the outer surface of the flush valve is made of a material that is can be readily fabricated. In one version, the outer surface of the flush valve is made of a material that can be fabricated by injection molding.

In one version, the flush valve is comprised of a material which has a modulus of between about 300 and 3000 psi. In one version, the flush valve is comprised of a material having a high environmental stress crack resistance (ESCR). In one version, the flush valve is comprised of a material having a high fatigue life.

In one version, the flush valve is comprised of a material having an operating temperature range of between about 32 and 120° F. In one version, the flush valve is comprised of a material having a low modulus change over a temperature range of between about 32 and 120° F.

In one version, the flush valve is comprised of a material that is readily moldable. In one version, the flush valve is comprised of a material that is readily blow moldable. In one version, the flush valve is comprised of a material that is readily injection moldable. In one version, the flush valve is comprised of a material that is readily blow moldable and injection moldable. In one version, the flush valve is comprised of a material that has a melt index above about 3. In one version, the flush valve is comprised of a material that has a melt index of approximately 10.

In one version, the flush valve is comprised of a material that has a relatively high toughness. In one version, the flush valve is comprised of a material that has a relatively high abrasion resistance. In one version, the flush valve is comprised of a material that has a relatively high puncture resistance.

Examples of thermoplastic materials are acetals, acrylics, cellulose acetates, the Nylons, polyolefins (such as polyethylene, polypropylene, polybutylene, t-butylene, their mixtures, alloys, and mixed copolymers and block copolymers), polystyrene, vinyl, and nylon amino, polycarbonate, polystyrene, ABS (acrylonitrile-butadiene-styrene), SAN (styrene-acrylonitrile), and PVC (polyvinylchloride). Thermoplastic elastomers (TPEs) may be particularly desirable. Thermoset materials include amino, epoxy, phenolic, and unsaturated polyesters. Thermoplastic Polyolefin Elastomers (TPOs) are also desirable. Characteristics of plastics materials can be changed by mixing or combining different types of polymers and by adding non-plastics materials such as particulate fillers and plasticizers.

Examples of rubber materials that may be used include, but are not limited to halogen-free diene rubbers, hydrogenation products of halogen-free diene rubbers, acrylic rubbers, epichlorohydrin rubbers, olefin rubbers, halogen-containing rubbers, silicone rubbers, pure rubbers, fluorinated rubbers, and fluorinated blends, etc. Mixtures of rubbers, and polymers may also be useful.

Examples of polyolefins and polyolefin copolymers that may be used include VLDPEs (for example, FLEXOMER DFDA-1095 NT from DOW Chemical Company, ExxonMobil EXACT resin 5371), ULDPE (for example, ATTANE 4404 G from DOW Chemical Company), bimodal polyethylene resin (e.g., Dow CONTINUUM), HDPE, LLDPE and polypropylene. Examples of soft vinyls that may be used include Tygon®.

The flush valve may also be coated with a material which provides protection or other advantages. For example, suitable coatings may improve resistance to corrosion and swelling, and otherwise enhance durability. Examples of coatings may include but are not limited to hydrophobic coatings (e.g. wax), polymeric coatings (e.g. Ethylene vinyl alcohol, etc.), and rubbery coatings (e.g. Silicones).

The flush valve may be colored or transparent. Although the color of the flush valve does not substantially affect the function, the flush valve may be made to have an aesthetically pleasing color, for example, by dying, painting, coating, etc.

Installation

A flush valve as described herein may be installed into the tank of a toilet by attaching the base region of the flush valve to the tank outlet port. In one version, the flush valve is attached to the outlet port by inserting the base region of the flush valve through the tank outlet port, and attaching applying pressure to seal the base region of the flush valve to the sides of the toilet outlet port. In one version, the base of the outlet port is threaded to attach to a nut. In versions of the flush valve in which the base of the flush valve is made of an elastomeric material, the flush valve may be sealed in the outlet port by clamping the base region of the flush valve against the tank, e.g. the sides of the outlet port. In one version, the flush valve is clamped to the outlet port by tightening a nut which compresses the base region of the flush valve against the walls of the outlet port. In one version, the inside of the base region of the flush valve threaded, and the base region of the flush valve is inserted into the tank outlet port and a threaded cylinder can be screwed into the base region to apply pressure sufficient to seal the base region into the tank outlet port. The threaded cylinder may be tapered so that the base region is slightly expanded as the cylinder is tightened, enhancing the seal.

The tank outlet port should be in fluid communication with the toilet bowl, so that fluid passing through the tank outlet port will enter the toilet bowl.

Operation

FIG. 6 illustrates an example of a flush valve installed in a toilet tank. In FIG. 6, the tank portion of the toilet is show partly cut away, revealing the water 601, flush valve 10, tipping actuator 605, and refilling inflow valve 607. The flush valve 10 is attached to the tank outlet port 611 at the base region of the flush valve, preventing water from entering the toilet bowl 620. The float region of the flush valve is buoyantly held above the surface of the water. The tipping actuator 605 in FIG. 6 is a rigid member attached to a handle 615. The end of the tipping actuator is on or above the edge of the top of the float region of the flush valve. Moving the handle 615 moves the tipping actuator, and thus, pushes down on the edge of one side of the flush valve, opening the flush valve.

The tipping actuator may be configured so that moving the handle on the outside of the toilet tank 615 downwards (as in most standard US toilet tanks) opens the flush valve. The tipping actuator may also include a spring, buoyant material, counterweight, or some combination thereof to return the actuator to the rest position immediately after flushing the toilet.

Although the tipping actuator is shown as a rigid member that may be pivoted by moving the handle, the tipping actuator may be any device capable of submerging at least one edge of the float region of the flush valve. The tipping actuator may submerge the entire float region. Thus, the tipping actuator may be a chain, lever arm, or plunger. It is preferable that the tipping actuator be controlled by the user from the side of the tank, for example by a handle means, as shown in FIG. 6. As will be apparent to those in the art, the handle means may be located anywhere on the toilet tank, including the top and sides. In addition to the components shown in FIG. 6, a toilet using a flush valve as described herein may include additional components, or other versions of the components shown in the FIG. 6. For example, the refilling inflow valve 607 may include a different float valve for detecting the fill level of the tank. An elbow joint may be attached to the inflow valve to apply water directly down the flush valve when the tank is being refilled.

FIG. 7A to 7C shows the flush valve being opened. In FIG. 7A, the flush valve is closed, but poised for activation by the tipping actuator 605. The collapsible flush valve is in the neutral position, fully extended. The tank is full of water 703, which is prevented from exiting the output port of the tank by the walls of the flush valve 10. In FIG. 7B the tipping actuator has been moved from its neutral resting position above (or on) the upper edge of the float region of the flush valve so that it contacts an edge of the float region of the flush valve. The tipping actuator applies sufficient force to the float region of the flush valve to overcome the buoyant forces keeping the float region above the water, and submerging at least part of the float region. Once the float region takes on water (as shown), the weight of the water also counteracts the buoyant forces of the float region, and top (float region) of the flush valve drops down towards the bottom of the tank as shown in FIG. 6C. The collapsible member of the flush valve collapses to permit the flush valve to sink. Water from the tank enters the flush valve, and drains out to the toilet bowl. Thus, the collapsible member of the flush valve collapses from the neutral extended position into the collapsed state.

The flush valve is turned off once the water in the tank has drained to a level approximately equal to the top of the float region, and the float region can no longer sink. Buoyancy of the float region is fully restored once the water in the float region (which is weighing down the float region) drains into the flush valve. As the tank is refilled through the tank inlet valve, the float region rises with the surface of the water in the tank. After the tank is completely refilled, the float region of the flush valve is once again at the top of the water level, and the flush valve is fully closed, and ready to be activated by the tipping actuator.

Although illustrative variations of the flush valve have been described above, it will be evident to a skilled artisan that various changes and modifications may be made without departing from the true scope and spirit of the flush valve described above and herein claimed. The various examples are, therefore, to be considered in all respects as illustrative and not restrictive. 

1. A flush valve for controllably delivering a selected amount of water to a toilet bowl from a toilet tank, the toilet tank having a water surface and a tank outlet, comprising: a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, wherein the collapsible member comprises one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions; and wherein the flush valve has no valve seat.
 2. The flush valve of claim 1, wherein the flush valve further comprises at least one ballast weight.
 3. The flush valve of claim 1, wherein the collapsible member is fabricated as a single piece by molding.
 4. The flush valve of claim 3, wherein the collapsible member is fabricated as a single piece by injection molding.
 5. The flush valve of claim 1, wherein the collapsible member is further configured to be relaxed in the extended position.
 6. The flush valve of claim 1, further comprising a tipping actuator for collapsing the collapsible member of the flush valve.
 7. The flush valve of claim 1 further comprising a base region and a float region that are fabricated with the collapsible member as a continuous single piece; and further wherein sinking the float region allows the collapsible member to collapse and allows water to flow through the collapsible member and out of the tank outlet.
 8. The flush valve of claim 7, wherein the base region, float region, and collapsible member are fabricated as a single piece by molding.
 9. The flush valve of claim 1, wherein the collapsible member is configured as a collapsible bellows.
 10. The flush valve of claim 9, wherein the collapsible bellows has a continuous spiral thread.
 11. The flush valve of claim 9, wherein the collapsible bellows is tapered.
 12. The flush valve of claim 1, wherein the flush valve is fabricated from a polyolefin.
 13. The flush valve of claim 12, wherein the flush valve is fabricated from a Very Low Density Polyethylene.
 14. The flush valve of claim 12, wherein the flush valve is fabricated from an Ultra Low Density Polyethylene.
 15. The flush valve of claim 1, wherein the flush valve is fabricated from soft vinyl.
 16. The flush valve of claim 1, further comprising a longitudinal shaft coupled to the collapsible member wherein the shaft is configured to substantially guide the flush valve when the collapsible member collapses.
 17. A method of using a flush valve in a toilet tank containing water comprising: at least partially sinking a flush valve comprising: a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, wherein the collapsible member comprises one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions.
 18. A flush valve for controllably delivering a selected amount of water to a toilet bowl from a toilet tank, the toilet tank having a water surface and a tank outlet, comprising: a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, and further configured to be relaxed in the extended position; and wherein the flush valve has no valve seat.
 19. The flush valve of claim 18 wherein the flush valve further comprises at least one ballast weight.
 20. The flush valve of claim 18 wherein the collapsible member is fabricated as a single piece by molding.
 21. The flush valve of claim 20, wherein the collapsible member is fabricated as a single piece by injection molding.
 22. The flush valve of claim 18, further comprising a tipping actuator for collapsing the collapsible member of the flush valve.
 23. The flush valve of claim 18 further comprising a base region and a float region that are fabricated with the collapsible member as a continuous single piece; and further wherein sinking the float region allows the collapsible member to collapse and allows water to flow through the collapsible member and out of the tank outlet.
 24. The flush valve of claim 23, wherein the base region, float region, and collapsible member are fabricated as a single piece by molding.
 25. The flush valve of claim 18, wherein the collapsible member is configured as a collapsible bellows.
 26. The flush valve of claim 25, wherein the collapsible bellows has a continuous spiral thread.
 27. The flush valve of claim 25, wherein the collapsible bellows is tapered.
 28. The flush valve of claim 18, further comprising a longitudinal shaft coupled to the collapsible member wherein the shaft is configured to substantially guide the flush valve when the collapsible member collapses.
 29. A method of using a flush valve in a toilet tank containing water comprising: at least partially sinking a flush valve comprising: a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, and further configured to be relaxed in the extended position.
 30. A flush valve for delivering water to a toilet bowl from a toilet tank comprising: a base region configured to connect to the outlet port of a toilet tank; a floatable and sinkable float region having an opening that is held above the surface of the water when the float region is floating, and wherein the float region is linked to the base region through a collapsible member extending from the base region to the float region; wherein the base region, float region and collapsible member are fabricated as a single piece, and further wherein sinking the float region allows water to flow through the opening of the float region and out of the outlet port of the toilet tank.
 31. The flush valve of claim 30 further comprising at least one ballast weight.
 32. The flush valve of claim 30, wherein the base region, float region and collapsible member are fabricated as a single piece by molding.
 33. The flush valve of claim 32, wherein the base region, float region and collapsible member are fabricated as a single piece by injection molding.
 34. The flush valve of claim 30, further comprising a tipping actuator for collapsing the collapsible member of the flush valve.
 35. The flush valve of claim 30, wherein the collapsible member is configured as a collapsible bellows.
 36. The flush valve of claim 35, wherein the collapsible bellows has a continuous spiral thread.
 37. The flush valve of claim 35, wherein the collapsible bellows is tapered.
 38. The flush valve of claim 30, further comprising a longitudinal shaft coupled to the collapsible member wherein the shaft is configured to substantially guide the flush valve when the collapsible member collapses.
 39. A method of using a flush valve comprising: at least partially sinking a float region of a flush valve in a toilet tank having an outlet port in fluid connection with a toilet bowl, the flush valve comprising: a base region configured to connect to an outlet port of the toilet tank; a variably buoyant float region configured to switch between a high buoyant state and a low buoyant state, and having an opening that is held above the surface of the water when the float region is highly buoyant, and further wherein the float region is linked to the base region through a collapsible member extending from the base region to the float region; wherein the float region and the collapsible member are fabricated as a single piece from one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions.
 40. A flush valve for controllably delivering a selected amount of water to a toilet bowl from a toilet tank, the toilet tank having a water surface and a tank outlet, comprising: a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position; and a ballast weight sufficient to collapse the collapsible member, wherein the flush valve has no valve seat.
 41. The flush valve of claim 40 wherein the collapsible member is fabricated as a single piece by molding.
 42. The flush valve of claim 41, wherein the collapsible member is fabricated as a single piece by injection molding.
 43. The flush valve of claim 40, further comprising a tipping actuator for collapsing the collapsible member of the flush valve.
 44. The flush valve of claim 40, wherein the collapsible member is configured as a collapsible bellows.
 45. The flush valve of claim 44, wherein the collapsible bellows has a continuous spiral thread.
 46. The flush valve of claim 44, wherein the collapsible bellows is tapered.
 47. The flush valve of claim 40, further comprising a longitudinal shaft coupled to the collapsible member wherein the shaft is configured to substantially guide the flush valve when the collapsible member collapses.
 48. A method of using a flush valve in a toilet tank containing water comprising: at least partially sinking a flush valve comprising: a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position; and a ballast weight sufficient to collapse the collapsible member.
 49. A flush valve for controllably delivering a selected amount of water to a toilet bowl from a toilet tank, the toilet tank having a water surface and a tank outlet, comprising: a molding-formed collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, and further configured to be spirally threaded, wherein the flush valve has no valve seat.
 50. The flush valve of claim 49 wherein the collapsible member is fabricated as a single piece by molding.
 51. The flush valve of claim 50, wherein the collapsible member is fabricated as a single piece by injection molding.
 52. The flush valve of claim 49, further comprising a tipping actuator for collapsing the collapsible member of the flush valve.
 53. The flush valve of claim 49, wherein the collapsible member is tapered.
 54. The flush valve of claim 49, further comprising a longitudinal shaft coupled to the collapsible member wherein the shaft is configured to substantially guide the flush valve when the collapsible member collapses.
 55. A method of using a flush valve in a toilet tank containing water comprising: at least partially sinking a flush valve comprising: a molding-formed collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, and further configured to be spirally threaded.
 56. A flush valve for controllably delivering a selected amount of water to a toilet bowl from a toilet tank, the toilet tank having a water surface and a tank outlet, comprising: a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, and further configured to be relaxed in the extended position, wherein the collapsible member comprises one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions; and wherein the flush valve has no valve seat.
 57. A flush valve for controllably delivering a selected amount of water to a toilet bowl from a toilet tank, the toilet tank having a water surface and a tank outlet, comprising: a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further configured to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, wherein the collapsible member comprises one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions, and wherein the collapsible member is fabricated as a single continuous piece; and wherein the flexible valve has no valve seat.
 58. A flush valve for controllably delivering a selected amount of water to a toilet bowl from a toilet tank, the toilet tank having a water surface and a tank outlet, comprising: a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further configured to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, wherein the collapsible member comprises one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions, and wherein the collapsible member is fabricated as a single continuous piece, and further wherein the collapsible member is configured to be substantially relaxed in the extended position.
 59. A flush valve for delivering water to a toilet bowl from a toilet tank comprising: a base region configured to connect to the outlet port of a toilet tank; a floatable and sinkable float region having an opening that is held above the surface of the water when the float region is floating, and wherein the float region is linked to the base region through a collapsible member extending from the base region to the float region; at least one ballast weight; wherein the collapsible member is relaxed in the extended position, and further wherein the base region, float region and collapsible member are fabricated as a single piece, and further wherein sinking the float region allows water to flow through the opening of the float region and out of the outlet port of the toilet tank.
 60. A flush valve for controllably delivering a selected amount of water to a toilet bowl from a toilet tank, the toilet tank having a water surface and a tank outlet, comprising: a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, further configured to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, and further configured to be relaxed in the extended position, and at least one ballast weight sufficient to collapse the collapsible member; wherein the collapsible member comprises one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions, and wherein a region of the collapsible member is configured as a collapsible bellows having at least one continuous thread, and wherein the collapsible member is fabricated as a single continuous piece by injection molding.
 61. A method of using a flush valve in a toilet tank containing water comprising: at least partially sinking a flush valve comprising: a collapsible member configured to extend from the water surface to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further configured to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, wherein the collapsible member comprises one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions, and wherein the collapsible member is fabricated as a single continuous piece, and further wherein the collapsible member is further configured to be substantially relaxed in the extended position.
 62. A method of installing a flush valve in a toilet tank having an outlet port in fluid connection with a toilet bowl comprising: providing a flush valve comprising: a base region configured to connect to the outlet port of a toilet tank; a variably buoyant float region configured to switch between a high buoyant state and a low buoyant state, and having an opening that is held above the surface of the water when the float region is highly buoyant, and further wherein the float region is linked to the base region through a collapsible member extending from the base region to the float region; wherein the float region and the collapsible member are fabricated as a single piece; installing the flush valve on the outlet port of a toilet tank.
 63. The method of claim 62 wherein the flush vale is installed by tightening a nut.
 64. A method of fabricating a flush valve comprising: injection molding a flush valve comprising: a base region configured to connect to the outlet port of a toilet tank; a variably buoyant float region configured to switch between a high buoyant state and a low buoyant state, and having an opening that is held above the surface of the water when the float region is highly buoyant, and further wherein the float region is linked to the base region through a collapsible member extending from the base region to the float region; wherein the float region, base region and the collapsible member are injection molded as a single piece.
 65. The method of claim 64 wherein the flush valve is injection molded from one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions.
 66. The method of claim 64 wherein the flush valve is tapered.
 67. A method of fabricating a flush valve comprising: injection molding a collapsible member configured to extend from the upper water surface of a substantially filled toilet tank to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further configured to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, wherein the collapsible member is further configured to be substantially relaxed in the extended position.
 68. The method of claim 66 wherein the collapsible member is injection molded from one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions.
 69. A method of fabricating a flush valve comprising: injection molding a collapsible member configured to extend from the upper water surface of a substantially filled toilet tank to the tank outlet in a first extended position and to maintain the water in the toilet tank, and further configured to release water from the toilet tank through the tank outlet in a second longitudinally collapsed position, wherein the collapsible member is injection molded from one or more materials that do not substantially deteriorate in the presence of halogen-containing toilet disinfectant solutions. 